A Great Treat Or Daily Diet For All Types Of Tropical Fish, Most Freshwater Fishes—Including, Cichlids, Discus, Betas and Goldfish. Bio-Pure FD is the worlds cleanest freeze-dried fish food available today. Pharmaceutical freeze-drying techniques allow us to give you a product as close to fresh as humanly possible. Expect a texture and taste not previously available in a freeze-dried food.